Storage system, method, and apparatus for processing operation request

ABSTRACT

According to a storage system, method, and apparatus for processing an operation request provided by embodiments of the present invention, a controller directly encapsulates a SCSI protocol operation request into an Ethernet operation request packet at the MAC layer instead of using the TCP/IP protocol layer and a disk enclosure decapsulates the Ethernet operation request to obtain the SCSI protocol operation request and sends the SCSI protocol operation request to a target disk, thereby reducing layers of encapsulation, reducing a processing delay of the storage system, and improving performance of the storage system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/728,178, filed on Jun. 2, 2015, which is a continuation ofInternational Application No. PCT/CN2014/084255, filed on Aug. 13, 2014.All of the afore-mentioned patent applications are hereby incorporatedby reference in their entireties.

TECHNICAL FIELD

The present invention relates to the field of information technologies,and in particular, to a storage system, a method, and an apparatus forprocessing an operation request.

BACKGROUND

The Internet Small Computer System Interface (iSCSI) protocol is anetwork storage protocol developed by the IETF, and is aimed atimplementing communication between storage devices using the InternetProtocol (IP). In a storage system, the Small Computer System Interface(SCSI) protocol is used on an IP protocol network for communication,that is, the iSCSI protocol is used for communication, which promotesdevelopment of storage technologies and implements long-distancetransmission of data. In one application scenario, a storage systemincludes a controller, a disk enclosure, and multiple disks. Thecontroller communicates with the disk enclosure using the iSCSIprotocol, the multiple disks are connected in the disk enclosure, andthe disk enclosure and the multiple disks connected in the diskenclosure are jointly called Just a Bunch Of Disks (JBOD). In thisscenario, the controller and the disk enclosure are separate, therebyimplementing flexible deployment.

The controller communicates with the disk enclosure using the iSCSIprotocol. For both the controller and the disk enclosure, the SCSIprotocol needs to be first encapsulated using the Transport ControlProtocol/Internet Protocol (TCP/IP), and then encapsulated by a mediaaccess control (MAC) layer. Similarly, a decapsulation process alsoinvolves MAC layer decapsulation and TCP/IP layer decapsulation.Multi-layer protocol encapsulation or decapsulation increases resourceconsumption of a Central Processing Unit (CPU) of the storage system anda processing delay of the storage system, and reduces performance of thestorage system.

SUMMARY

Embodiments of the present invention provide a storage system, a method,and an apparatus for processing an operation request.

According to a first aspect, an embodiment of the present inventionprovides a storage system for processing an operation request, where thestorage system includes a controller and a disk enclosure, and thecontroller communicates with the disk enclosure using an Ethernetnetwork. The controller includes a central processing unit and aback-end adapter. The disk enclosure and the back-end adapter each havea media access control (MAC) address. Multiple disks are connected inthe disk enclosure, and each disk in the disk enclosure is connected tothe disk enclosure using the Serial Attached Small Computer SystemInterface (SAS) protocol. The back-end adapter stores a correspondencebetween the MAC address of the disk enclosure and a SAS protocol addressof each disk in the disk enclosure. The back-end adapter is configuredto receive a Small Computer System Interface (SCSI) protocol operationrequest sent by the central processing unit, where the SCSI protocoloperation request carries a SCSI protocol transaction identifier of thecontroller and a SAS protocol address of a target disk, query acorrespondence between the MAC address of the disk enclosure and the SASprotocol address of the target disk according to the SAS protocoladdress of the target disk to obtain the MAC address of the diskenclosure, encapsulate the SCSI protocol operation request into anEthernet operation request packet, and send the Ethernet operationrequest packet to the disk enclosure according to the MAC address of thedisk enclosure. The Ethernet operation request packet carries the MACaddress of the back-end adapter and the MAC address of the diskenclosure. The disk enclosure is configured to receive and decapsulatethe Ethernet operation request packet to obtain the SCSI protocoloperation request, and send the SCSI protocol operation request to thetarget disk according to the SAS protocol address of the target disk.

In a first implementation of the first aspect, the disk enclosure isfurther configured to establish a correspondence between the MAC addressof the back-end adapter and the SCSI protocol transaction identifier ofthe controller. The disk enclosure is further configured to receive aSCSI protocol operation request response that is sent by the target diskaccording to the SCSI protocol operation request, where the SCSIprotocol operation request response carries the SCSI protocoltransaction identifier of the controller, query the correspondencebetween the MAC address of the back-end adapter and the SCSI protocoltransaction identifier of the controller according to the SCSI protocoltransaction identifier of the controller to obtain the MAC address ofthe back-end adapter, encapsulate the SCSI protocol operation requestresponse into an Ethernet operation request response packet, and sendthe Ethernet operation request response packet to the controlleraccording to the MAC address of the back-end adapter. The Ethernetoperation request response packet carries the MAC address of theback-end adapter. The back-end adapter is further configured to receiveand decapsulate the Ethernet operation request response packet to obtainthe SCSI protocol operation request response, and send the SCSI protocoloperation request response to the central processing unit.

In a second implementation of the first aspect, the back-end adapter isfurther configured to encapsulate the SCSI protocol transactionidentifier of the controller in the SCSI protocol operation request intoa first field of the Ethernet operation request packet and encapsulatethe SAS protocol address of the target disk in the SCSI protocoloperation request into a second field of the Ethernet operation requestpacket. The first field, the second field, and a field carrying the SCSIprotocol operation request are three different fields. That the diskenclosure establishes a correspondence between the MAC address of theback-end adapter and the SCSI protocol transaction identifier of thecontroller includes the disk enclosure decapsulates the first field ofthe Ethernet operation request packet to obtain the SCSI protocoltransaction identifier of the controller and establishes thecorrespondence between the MAC address of the back-end adapter and theSCSI protocol transaction identifier of the controller. That the diskenclosure sends the SCSI protocol operation request to the target diskaccording to the SAS protocol address of the target disk includes thedisk enclosure decapsulates the second field of the Ethernet operationrequest packet to obtain the SAS protocol address of the target disk andsends the SCSI protocol operation request to the target disk accordingto the SAS protocol address of the target disk.

According to a second aspect, an embodiment of the present inventionprovides a method for processing an operation request, where the methodis applied to a controller. The controller communicates with a diskenclosure using an Ethernet network. The controller includes a centralprocessing unit and a back-end adapter. The disk enclosure and theback-end adapter each have a media access control MAC address. Multipledisks are connected in the disk enclosure. Each disk in the diskenclosure is connected to the disk enclosure using the Serial AttachedSmall Computer System Interface SAS protocol. The back-end adapterstores a correspondence between the MAC address of the disk enclosureand a SAS protocol address of each disk in the disk enclosure. Themethod includes sending, by the central processing unit, a SmallComputer System Interface SCSI protocol operation request, where theSCSI protocol operation request carries a SAS protocol address of atarget disk, and receiving, by the back-end adapter, the SCSI protocoloperation request sent by the central processing unit, querying acorrespondence between the MAC address of the disk enclosure and the SASprotocol address of the target disk according to the SAS protocoladdress of the target disk to obtain the MAC address of the diskenclosure, encapsulating the SCSI protocol operation request into anEthernet operation request packet carrying the MAC address of theback-end adapter and the MAC address of the disk enclosure, and sendingthe Ethernet operation request packet to the disk enclosure according tothe MAC address of the disk enclosure.

In a first implementation of the second aspect, the SCSI protocoloperation request further carries a SCSI protocol transaction identifierof the controller. The method further includes encapsulating the SCSIprotocol transaction identifier of the controller into a first field ofthe Ethernet operation request packet and encapsulating the SAS protocoladdress of the target disk into a second field of the Ethernet operationrequest packet. The first field, the second field, and a field that isin the Ethernet operation request packet and carries the SCSI protocoloperation request are three different fields.

In a second implementation, the method further includes receiving anddecapsulating, by the back-end adapter, an Ethernet response packet forthe Ethernet operation request packet that is sent by the disk enclosureto obtain a SCSI protocol operation request response, sending the SCSIprotocol operation request response to the central processing unit,where the Ethernet response packet for the Ethernet operation requestpacket carries the MAC address of the back-end adapter, and receiving,by the central processing unit, the SCSI protocol operation requestresponse.

According to a third aspect, an embodiment of the present inventionprovides a method for processing an operation request, where the methodis applied to a disk enclosure. A controller communicates with the diskenclosure using an Ethernet network. The controller includes a centralprocessing unit and a back-end adapter. The disk enclosure and theback-end adapter each have a media access control MAC address. Multipledisks are connected in the disk enclosure and each disk in the diskenclosure is connected to the disk enclosure using the Serial AttachedSmall Computer System Interface SAS protocol. receiving anddecapsulating, by the disk enclosure, an Ethernet operation requestpacket sent by the controller to obtain a Small Computer SystemInterface SCSI protocol operation request, where the Ethernet operationrequest packet carries the MAC address of the back-end adapter and theMAC address of the disk enclosure, and the SCSI protocol operationrequest carries a SCSI protocol transaction identifier of the controllerand a SAS protocol address of a target disk, and sending, by the diskenclosure, the SCSI protocol operation request to the target diskaccording to the SAS protocol address of the target disk.

The method includes

In a first implementation of the third aspect, the method furtherincludes establishing, by the disk enclosure, a correspondence betweenthe MAC address of the back-end adapter and the SCSI protocoltransaction identifier of the controller, receiving, by the diskenclosure, a SCSI protocol operation request response that is sent bythe target disk according to the SCSI protocol operation request, wherethe SCSI protocol operation request response carries the SCSI protocoltransaction identifier of the controller, querying, by the diskenclosure, the correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controlleraccording to the SCSI protocol transaction identifier of the controllerto obtain the MAC address of the back-end adapter, encapsulating, by thedisk enclosure, the SCSI protocol operation request response into anEthernet operation request response packet, where the Ethernet operationrequest response packet carries the MAC address of the back-end adapter,and sending, by the disk enclosure, the Ethernet operation requestresponse packet to the controller according to the MAC address of theback-end adapter.

In a second implementation of the third aspect, a first field of theEthernet operation request packet carries the SCSI protocol transactionidentifier of the controller and a second field of the Ethernetoperation request packet carries the SAS protocol address of the targetdisk. The first field, the second field, and a field that is in theEthernet operation request packet and carries the SCSI protocoloperation request are three different fields. The establishing, by thedisk enclosure, a correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controllerincludes decapsulating, by the disk enclosure, the first field of theEthernet operation request packet to obtain the SCSI protocoltransaction identifier of the controller and establishing thecorrespondence between the MAC address of the back-end adapter and theSCSI protocol transaction identifier of the controller, and the sending,by the disk enclosure, the SCSI protocol operation request to the targetdisk according to the SAS protocol address of the target disk includesdecapsulating, by the disk enclosure, the second field of the Ethernetoperation request packet to obtain the SAS protocol address of thetarget disk and sending the SCSI protocol operation request to thetarget disk according to the SAS protocol address of the target disk.

According to a fourth aspect, an embodiment of the present inventionprovides a controller, where the controller is applied to a storagesystem. The storage system includes the controller and a disk enclosure.The controller communicates with the disk enclosure using an Ethernetnetwork. The controller includes a central processing unit and aback-end adapter. The disk enclosure and the back-end adapter each havea media access control MAC address. Multiple disks are connected in thedisk enclosure, and each disk in the disk enclosure is connected to thedisk enclosure using the Serial Attached Small Computer System InterfaceSAS protocol. The back-end adapter stores a correspondence between theMAC address of the disk enclosure and a SAS protocol address of eachdisk in the disk enclosure. The central processing unit is configured tosend a Small Computer System Interface SCSI protocol operation request,where the SCSI protocol operation request carries a SAS protocol addressof a target disk. The back-end adapter is configured to receive the SCSIprotocol operation request, query a correspondence between the MACaddress of the disk enclosure and the SAS protocol address of the targetdisk according to the SAS protocol address of the target disk to obtainthe MAC address of the disk enclosure, encapsulate the SCSI protocoloperation request into an Ethernet operation request packet, and sendthe Ethernet operation request packet to the disk enclosure according tothe MAC address of the disk enclosure, where the Ethernet operationrequest packet carries the MAC address of the back-end adapter and theMAC address of the disk enclosure.

In a first implementation of the fourth aspect, the SCSI protocoloperation request further carries a SCSI protocol transaction identifierof the controller. The back-end adapter is further configured toencapsulate the SCSI protocol transaction identifier of the controllerinto a first field of the Ethernet operation request packet andencapsulate the SAS protocol address of the target disk into a secondfield of the Ethernet operation request packet, where the first field,the second field, and a field that is in the Ethernet operation requestpacket and carries the SCSI protocol operation request are threedifferent fields.

In a second implementation of the fourth aspect, the back-end adapter isfurther configured to receive and decapsulate an Ethernet responsepacket for the Ethernet operation request packet that is sent by thedisk enclosure to obtain a SCSI protocol operation request response, andsend the SCSI protocol operation request response to the centralprocessing unit, where the Ethernet response packet for the Ethernetoperation request packet carries the MAC address of the back-endadapter, and the central processing unit is further configured toreceive the SCSI protocol operation request response.

According to a fifth aspect, an embodiment of the present inventionprovides a disk enclosure, where the disk enclosure is applied to astorage system, and the storage system includes a controller and thedisk enclosure. The controller includes a central processing unit and aback-end adapter. The disk enclosure and the back-end adapter each havea media access control MAC address. Multiple disks are connected in thedisk enclosure, and each disk in the disk enclosure is connected to thedisk enclosure using the Serial Attached Small Computer System InterfaceSAS protocol. The controller communicates with the disk enclosure usingan Ethernet network. The disk enclosure includes a first transceiverunit configured to receive an Ethernet operation request packet sent bythe controller, where the Ethernet operation request packet carries theMAC address of the back-end adapter and the MAC address of the diskenclosure, an encapsulating and decapsulating unit, configured todecapsulate the Ethernet operation request packet received by the firsttransceiver unit to obtain a Small Computer System Interface SCSIprotocol operation request, where the SCSI protocol operation requestcarries a SCSI protocol transaction identifier of the controller and aSAS protocol address of a target disk, and a second transceiver unit,configured to send the SCSI protocol operation request to the targetdisk according to the SAS protocol address of the target disk.

In a first implementation of the fifth aspect, the disk enclosurefurther includes an establishing unit and a querying unit, where theestablishing unit is configured to establish a correspondence betweenthe MAC address of the back-end adapter and the SCSI protocoltransaction identifier of the controller, the second transceiver unit isfurther configured to receive a SCSI protocol operation request responsethat is sent by the target disk according to the SCSI protocol operationrequest, where the SCSI protocol operation request response carries theSCSI protocol transaction identifier of the controller, the queryingunit is configured to query, according to the SCSI protocol transactionidentifier of the controller, the correspondence between the MAC addressof the back-end adapter and the SCSI protocol transaction identifier ofthe controller that is established by the establishing unit, to obtainthe MAC address of the back-end adapter, the encapsulating anddecapsulating unit is further configured to encapsulate the SCSIprotocol operation request response into an Ethernet operation requestresponse packet, where the Ethernet operation request response packetcarries the MAC address of the back-end adapter, and the firsttransceiver unit is further configured to send the Ethernet operationrequest response packet to the controller according to the MAC addressof the back-end adapter.

In a second implementation of the fifth aspect, a first field of theEthernet operation request packet carries the SCSI protocol transactionidentifier of the controller and a second field of the Ethernetoperation request packet carries the SAS protocol address of the targetdisk, where the first field, the second field, and a field that is inthe Ethernet operation request packet and carries the SCSI protocoloperation request are three different fields, that the establishing unitestablishes a correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controllerincludes the encapsulating and decapsulating unit decapsulates the firstfield of the Ethernet operation request packet to obtain the SCSIprotocol transaction identifier of the controller, and the establishingunit establishes the correspondence between the MAC address of theback-end adapter and the SCSI protocol transaction identifier of thecontroller, and that the second transceiver unit sends the SCSI protocoloperation request to the target disk according to the SAS protocoladdress of the target disk includes the encapsulating and decapsulatingunit decapsulates the second field of the Ethernet operation requestpacket, to obtain the SAS protocol address of the target disk, and thesecond transceiver unit sends the SCSI protocol operation request to thetarget disk according to the SAS protocol address of the target disk.

According to a sixth aspect, an embodiment of the present inventionprovides a back-end adapter, where the back-end adapter is applied to acontroller of a storage system, and the storage system includes thecontroller and a disk enclosure. The controller communicates with thedisk enclosure using an Ethernet network. The controller includes acentral processing unit and the back-end adapter. The disk enclosure andthe back-end adapter each have a media access control MAC address.Multiple disks are connected in the disk enclosure, and each disk in thedisk enclosure is connected to the disk enclosure using the SerialAttached Small Computer System Interface SAS protocol. The back-endadapter stores a correspondence between the MAC address of the diskenclosure and a SAS protocol address of each disk in the disk enclosure.The back-end adapter includes a first transceiver unit, configured tosend a Small Computer System Interface SCSI protocol operation request,where the SCSI protocol operation request carries a SAS protocol addressof a target disk, a querying unit, configured to query a correspondencebetween the MAC address of the disk enclosure and the SAS protocoladdress of the target disk, to obtain the MAC address of the diskenclosure, an encapsulating and decapsulating unit, configured toencapsulate the SCSI protocol operation request into an Ethernetoperation request packet, where the Ethernet operation request packetcarries the MAC address of the back-end adapter and the MAC address ofthe disk enclosure, and a second transceiver unit, configured to sendthe Ethernet operation request packet to the disk enclosure according tothe MAC address of the disk enclosure.

In a first implementation of the sixth aspect, the SCSI protocoloperation request further carries a SCSI protocol transaction identifierof the controller. The encapsulating and decapsulating unit is furtherconfigured to encapsulate the SCSI protocol transaction identifier ofthe controller into a first field of the Ethernet operation requestpacket and encapsulate the SAS protocol address of the target disk intoa second field, where the first field, the second field, and a fieldthat is in the Ethernet operation request packet and carries the SCSIprotocol operation request are three different fields.

In a second implementation of the sixth aspect, the second transceiverunit is further configured to receive an Ethernet response packet forthe Ethernet operation request packet that is sent by the diskenclosure, where the Ethernet response packet for the Ethernet operationrequest packet carries the MAC address of the back-end adapter, theencapsulating and decapsulating unit is further configured todecapsulate the Ethernet response packet for the Ethernet operationrequest packet, to obtain a SCSI protocol operation request response,and the first transceiver unit is further configured to send the SCSIprotocol operation request response to the central processing unit.

According to a seventh aspect, an embodiment of the present inventionprovides a back-end adapter, where the back-end adapter is applied to acontroller of a storage system, and the storage system includes thecontroller and a disk enclosure. The controller communicates with thedisk enclosure using an Ethernet network. The controller includes acentral processing unit and the back-end adapter. The disk enclosure andthe back-end adapter each have a media access control MAC address.Multiple disks are connected in the disk enclosure, and each disk in thedisk enclosure is connected to the disk enclosure using the SerialAttached Small Computer System Interface SAS protocol. The back-endadapter stores a correspondence between the MAC address of the diskenclosure and a SAS protocol address of each disk in the disk enclosure.The back-end adapter includes a first interface, a second interface, amemory, and a first central processing unit, where the first interfaceis configured to receive a Small Computer System Interface SCSI protocoloperation request sent by the central processing unit, where the SCSIprotocol operation request carries a SAS protocol address of a targetdisk. The first central processing unit executes a computer instructionin the memory, querying a correspondence between the MAC address of thedisk enclosure and the SAS protocol address of the target disk accordingto the SAS protocol address of the target disk to obtain the MAC addressof the disk enclosure, and encapsulating the SCSI protocol operationrequest into an Ethernet operation request packet, where the Ethernetoperation request packet carries the MAC address of the back-end adapterand the MAC address of the disk enclosure. The second interface isconfigured to send the Ethernet operation request packet to the diskenclosure according to the MAC address of the disk enclosure.

In a first implementation of the seventh aspect, the SCSI protocoloperation request further carries a SCSI protocol transaction identifierof the controller. The first central processing unit executes thecomputer instruction in the memory, encapsulating the SCSI protocoltransaction identifier of the controller into a first field of theEthernet operation request packet, and encapsulating the SAS protocoladdress of the target disk into a second field, where the first field,the second field, and a field that is in the Ethernet operation requestpacket and carries the SCSI protocol operation request are threedifferent fields.

In a second implementation of the seventh aspect, the second interfaceis further configured to receive an Ethernet response packet for theEthernet operation request packet that is sent by the disk enclosure,where the Ethernet response packet for the Ethernet operation requestpacket carries the MAC address of the back-end adapter. The firstcentral processing unit executes the computer instruction in the memory,decapsulating the Ethernet response packet for the Ethernet operationrequest packet to obtain a SCSI protocol operation request response, andthe first interface is further configured to send the SCSI protocoloperation request response to the central processing unit.

According to an eighth aspect, an embodiment of the present inventionprovides a disk enclosure, where the disk enclosure is applied to astorage system. The storage system includes a controller and the diskenclosure. The controller communicates with the disk enclosure using anEthernet network. The controller includes a central processing unit anda back-end adapter. The disk enclosure and the back-end adapter eachhave a media access control MAC address. Multiple disks are connected inthe disk enclosure, and each disk in the disk enclosure is connected tothe disk enclosure using the Serial Attached Small Computer SystemInterface SAS protocol. The disk enclosure includes a front-endinterface, a back-end interface, a first central processing unit, and afirst memory. The front-end interface is configured to receive anddecapsulate an Ethernet operation request packet sent by the controller,to obtain a Small Computer System Interface SCSI protocol operationrequest, and send the SCSI protocol operation request to the firstcentral processing unit. The Ethernet operation request packet carriesthe MAC address of the back-end adapter and the MAC address of the diskenclosure. The SCSI protocol operation request carries a SCSI protocoltransaction identifier of the controller and a SAS protocol address of atarget disk. The first central processing unit executes a computerinstruction in the first memory, receiving the SCSI protocol operationrequest, and sending the SCSI protocol operation request to the back-endinterface. The back-end interface is configured to receive the SCSIprotocol operation request, and send the SCSI protocol operation requestto the target disk according to the SAS protocol address of the targetdisk.

In a first implementation of the eighth aspect, the first centralprocessing unit executes the computer instruction in the first memory,establishing a correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controller.The back-end interface is configured to send the SCSI protocol operationrequest to the target disk according to the SAS protocol address of thetarget disk. The back-end interface is further configured to receive aSCSI protocol operation request response that is sent by the target diskaccording to the SCSI protocol operation request, where the SCSIprotocol operation request response carries the SCSI protocoltransaction identifier of the controller. The first central processingunit executes the computer instruction in the first memory, querying thecorrespondence between the MAC address of the back-end adapter and theSCSI protocol transaction identifier of the controller according to theSCSI protocol transaction identifier of the controller carried in theSCSI protocol operation request response, to obtain the MAC address ofthe back-end adapter. The front-end interface is further configured to:receive the SCSI protocol operation request response sent by the firstcentral processing unit, encapsulate the SCSI protocol operation requestresponse into an Ethernet operation request response packet according tothe MAC address of the back-end adapter that is obtained by the firstcentral processing unit, and send the Ethernet operation requestresponse packet to the controller according to the MAC address of theback-end adapter. The Ethernet operation request response packet carriesthe MAC address of the back-end adapter.

In a second implementation of the eighth aspect, a first field of theEthernet operation request packet carries the SCSI protocol transactionidentifier of the controller, and a second field of the Ethernetoperation request packet carries the SAS protocol address of the targetdisk, where the first field, the second field, and a field that is inthe Ethernet operation request packet and carries the SCSI protocoloperation request are three different fields. Establishing acorrespondence between the MAC address of the back-end adapter and theSCSI protocol transaction identifier of the controller includesdecapsulating, by the front-end interface, the first field of theEthernet operation request packet, to obtain the SCSI protocoltransaction identifier of the controller, and establishing, by anestablishing unit of the first central processing unit, thecorrespondence between the MAC address of the back-end adapter and theSCSI protocol transaction identifier of the controller. The back-endinterface sending the SCSI protocol operation request to the target diskaccording to the SAS protocol address of the target disk includes thefront-end interface decapsulating the second field of the Ethernetoperation request packet, to obtain the SAS protocol address of thetarget disk, and the back-end interface sending the SCSI protocoloperation request to the target disk according to the SAS protocoladdress of the target disk.

According to the storage system, method, and apparatus for processing anoperation request provided by the embodiments of the present invention,a controller directly encapsulates a SCSI protocol operation requestinto an Ethernet operation request packet at the MAC layer instead ofusing the TCP/IP protocol layer. A disk enclosure decapsulates theEthernet operation request to obtain the SCSI protocol operation requestand sends the SCSI protocol operation request to a target disk, therebyreducing layers of encapsulation, reducing a processing delay of thestorage system, and improving performance of the storage system.

BRIEF DESCRIPTION OF DRAWINGS

To describe the technical solutions in the embodiments of the presentinvention more clearly, the following briefly introduces theaccompanying drawings required for describing the embodiments.

FIG. 1 is a diagram of a storage system embodiment;

FIG. 2 is a diagram of a controller embodiment;

FIG. 3a and FIG. 3b are diagrams of a disk enclosure embodiment;

FIG. 4 is a table of correspondence between a SCSI protocol transactionidentifier of a controller and a MAC address of a back-end adapter;

FIG. 5A and FIG. 5B are flowcharts of communication among a controller,a disk enclosure, and a target disk according to an embodiment;

FIG. 6 is a flowchart of collection of a MAC address of a disk enclosureand a SAS protocol address of a disk that communicates with the diskenclosure by a controller using a heartbeat broadcast packet, accordingto an embodiment;

FIG. 7 is a diagram of a packet format of a heartbeat broadcast packetembodiment;

FIG. 8 is a diagram of a packet format of a heartbeat broadcast packetresponse embodiment;

FIG. 9 is a table of a correspondence between a MAC address of a diskenclosure and a SAS protocol address of a disk that communicates withthe disk enclosure;

FIG. 10 is a diagram of a controller embodiment;

FIG. 11 is a diagram of a back-end adapter embodiment;

FIG. 12 is a diagram of a packet format of an Ethernet operation requestinto which a SCSI protocol operation request is encapsulated, accordingto an embodiment;

FIG. 13 is a diagram of a back-end adapter embodiment; and

FIG. 14 is a diagram of a storage system embodiment.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present invention with reference to the accompanyingdrawings. The described embodiments are merely some but not all of theembodiments of the present invention.

As shown in FIG. 1, a storage system provided by an embodiment of thepresent invention includes a controller 101 and a disk enclosure 102,where multiple disks 1031 . . . 103 n, 1041 . . . 104 n are connected inthe disk enclosure 102, and n is defined according to requirements ofthe storage system. In terms of the expression “multiple disks 1031 . .. 103 n, 1041 . . . 104 n are connected in the disk enclosure 102”,another expression is: multiple disks 1031 . . . 103 n, 1041 . . . 104 nare disposed in the disk enclosure 102, and the disks 1031 . . . 103 n,1041 . . . 104 n are communicatively connected to the disk enclosure102. The controller 101 communicates with the disk enclosure 102 usingan Ethernet network, and the disks 1031 . . . 103 n, 1041 . . . 104 nare connected to the disk enclosure 102 using a Serial Attached SmallComputer System Interface (SAS). For detailed descriptions of the SASprotocol, refer to the SAS Protocol Layer-2 (SPL-2) standard(http://www.t10.org/members/w_spl2.htm). The disks 1031 . . . 103 n,1041 . . . 104 n may be magnetic disks, optical disks or optical storagemedia, solid-state storage, other storage media, or combinations of theforegoing storage media, which is not limited by this embodiment of thepresent invention.

As shown in FIG. 2, an exemplary structure of the controller 101includes a front-end adapter 1011, a central processing unit 1012, amemory 1013, and a back-end adapter 1014. The front-end adapter 1011communicates with a server, and is configured to receive a read requestsent by the server and return data to the server according to the readrequest, or is configured to receive a write request sent by the serverand send a response to the server according to the write request. Thecentral processing unit 1012 is configured to process, according to acomputer instruction in the memory 1013, a read request and a writerequest that are received by the front-end adapter, or is configured tosend an operation request to a disk in the disk enclosure 102 or receivean operation request response sent by the disk enclosure 102. Theback-end adapter 1014 is configured to communicate with the diskenclosure 102 using an Ethernet network.

As shown in FIG. 3a , the disk enclosure 102 includes a front-endinterface 1021, a central processing unit 1022, a memory 1023, and aback-end interface 1024. The disk enclosure 102 communicates with thecontroller 101 using the front-end interface 1021. The back-endinterface 1024 is configured to communicate with disks 1031 . . . 103 n,1041 . . . 104 n. The central processing unit 1022 is configured toprocess a read operation request or a write operation request that isfrom the controller 101 and based on a first protocol, send, accordingto the read operation request or write operation request, a readoperation request or a write operation request that is based on a secondprotocol to a target disk among the disks 1031 . . . 103 n, 1041 . . .104 n; and send, according to a read operation request response or awrite operation request response that is sent by the target disk andbased on the second protocol, a read operation request response or awrite operation request response that is based on the first protocol tothe controller 101. The first protocol and the second protocol may bedifferent protocols and are specifically determined by an applicationscenario. In one embodiment, the first protocol is an Ethernetcommunications protocol, and the second protocol is the SAS protocol.The back-end interface 1024 of the disk enclosure 102 communicates withSAS protocol interfaces of the disks 1031 . . . 103 n, 1041 . . . 104 nusing the SCSI protocol and a SAS protocol interface. Specifically, thefront-end interface 1021 of the disk enclosure 102 is configured toreceive and decapsulate an Ethernet operation request packet sent by thecontroller 101, obtain a SCSI protocol operation request, and send theSCSI protocol operation request to the central processing unit 1022. TheEthernet operation request packet carries a MAC address of the back-endadapter 1014 and a MAC address of the disk enclosure 102. The SCSIprotocol operation request carries a SCSI protocol transactionidentifier of the controller 101 and a SAS protocol address of a targetdisk 1031, where the SCSI protocol transaction identifier is used touniquely identify a specific SCSI protocol transaction link establishedbetween the controller 101 and the target disk 1031. The target disk1031 refers to a disk accessed by the SCSI protocol operation request.

The processing unit 1022 executes a computer instruction in the memory1023, to implement the following operations: receiving the SCSI protocoloperation request, establishing a correspondence between the MAC addressof the back-end adapter 1014 and the SCSI protocol transactionidentifier of the controller 101, and sending the SCSI protocoloperation request to the back-end interface 1024 according to the SASprotocol address of the target disk 1031. According to the SAS protocoladdress of the target disk 1031, an implementation manner comprisesparsing the SCSI protocol operation request to obtain the SAS protocoladdress of the target disk 1031.

The back-end interface 1024 is configured to receive the SCSI protocoloperation request and send the SCSI protocol operation request to thetarget disk 1031. The back-end interface 1024 is further configured toreceive a SCSI protocol operation request response that is sent by thetarget disk 1031 according to the SCSI protocol operation request, wherethe SCSI protocol operation request response carries the SCSI protocoltransaction identifier of the controller 101.

Correspondingly, the central processing unit 1022 executes the computerinstruction in the memory 1023, and further implements the followingoperation: querying the correspondence between the MAC address of theback-end adapter 1014 and the SCSI protocol transaction identifier ofthe controller 101 according to the SCSI protocol transaction identifierof the controller 101 carried in the SCSI protocol operation requestresponse, to obtain the MAC address of the back-end adapter 1014; andthe front-end interface 1201 is further configured to: receive the SCSIprotocol operation request response sent by the central processing unit1022; encapsulate, according to the MAC address of the back-end adapter1014 obtained by the central processing unit 1022, the SCSI protocoloperation request response into an Ethernet operation request responsepacket that carries the MAC address of the back-end adapter 1014; andsend the Ethernet operation request response packet to the controller101 according to the MAC address of the back-end adapter 1014.

In another implementation, the back-end adapter 1014 encapsulates theSCSI protocol operation request into the Ethernet operation requestpacket, encapsulates the SCSI protocol transaction identifier of thecontroller 101 carried in the SCSI protocol operation request into afirst field of the Ethernet operation request packet, encapsulates theSAS protocol address of the target disk 1031 into a second field, andsends the Ethernet operation request packet to the disk enclosure 102,where the first field, the second field, and a field carrying the SCSIprotocol operation request are three different fields. The diskenclosure 102 decapsulates the Ethernet operation request packet,obtains the SAS protocol address of the target disk from the foregoingsecond field, instead of parsing the field carrying the SCSI protocoloperation request to obtain the SCSI protocol transaction identifier ofthe controller 101 and the SAS protocol address of the target disk fromthe SCSI protocol operation request, and sends the SCSI protocoloperation request to the target disk according to the SAS protocoladdress of the target disk. The disk enclosure 102 obtains the SCSIprotocol transaction identifier of the controller 101 from the foregoingfirst field, and establishes the correspondence between the SCSIprotocol transaction identifier of the controller 101 and the MACaddress of the back-end adapter 1014 according to the SCSI protocoltransaction identifier of the controller 101 obtained from the foregoingfirst field. In this implementation manner, after decapsulating theEthernet operation request packet, the disk enclosure 102 can establishthe correspondence between the SCSI protocol transaction identifier ofthe controller 101 and the MAC of the back-end adapter 101, and send theSCSI protocol operation request to the target disk, without a need toparse the SCSI protocol operation request, thereby saving computationresources of the disk enclosure 102.

Exemplarily, the central processing unit 1022 of the disk enclosure 102establishes the correspondence between the SCSI protocol transactionidentifier of the controller 101 and the MAC address of the back-endadapter 1014. As shown in FIG. 4, the correspondence between the SCSIprotocol transaction identifier of the controller 101 and the MACaddress of the back-end adapter 1014 is stored in a form of atwo-dimensional table. In specific computer implementation, thetwo-dimensional table may be stored in a form of a two-dimensional arrayor in a form that can be recognized by a computer, which is not limitedby this embodiment of the present invention. Packet formats of the SCSIprotocol operation request response packet and the Ethernet operationrequest response packet respectively correspond to those of the SCSIprotocol operation request and the Ethernet operation request. Aspecific difference lies in different content carried in packet fields.When in the Ethernet operation request packet, the first field is usedto carry the SCSI protocol transaction identifier of the controller, andthe second field is used to carry the destination SAS protocol address,in the Ethernet operation request response packet, a first field stillcarries the SCSI protocol transaction identifier of the controller, andthe destination SAS protocol address in a second field is empty.

The disk enclosure 102 described in FIG. 3a of the embodiment of thepresent invention may be implemented by a computer having a generalcentral processing unit, as shown in FIG. 3a . In another aspect, thedisk enclosure 102 may be implemented jointly by an application-specificintegrated circuit (ASIC), namely an ASIC commercial chip, and a memory,or may be implemented by a Field Programmable Gate Array (FPGA). Interms of logical division, the disk enclosure 102 includes a processingfunction, namely a central processing unit, and a memory in which aprocessing instruction is stored.

As shown in FIG. 3b , another logical presentation of a structure of thedisk enclosure 102 based on the structure of the disk enclosure 102shown in FIG. 3a includes a first transceiver unit 1021′, anencapsulating and decapsulating unit 1022′, and a second transceiverunit 1024′.

The first transceiver unit 1021′ is configured to receive an Ethernetoperation request packet sent by the controller 101, where the Ethernetoperation request packet carries a MAC address of the back-end adapter1014 and a MAC address of the disk enclosure 102.

The encapsulating and decapsulating unit 1022′ is configured todecapsulate the Ethernet operation request packet received by the firsttransceiver unit 1021′, and obtain a SCSI protocol operation request,where the SCSI protocol operation request carries a SCSI protocoltransaction identifier of the controller 101 and a SAS protocol addressof a target disk 1031.

The second transceiver unit 1024′ is configured to send the SCSIprotocol operation request to the target disk 1031 according to the SASprotocol address of the target disk 1031. Further, the disk enclosure102 further includes an establishing unit 1023′ and a querying unit1025′. The establishing unit 1023′ is configured to establish acorrespondence between the MAC address of the back-end adapter 1014 andthe SCSI protocol transaction identifier of the controller 101. Further,the second transceiver unit 1024′ is further configured to receive aSCSI protocol operation request response that is sent by the target disk1031 according to the SCSI protocol operation request, where the SCSIprotocol operation request response carries the SCSI protocoltransaction identifier of the controller 101. The querying unit 1025′ isconfigured to query, according to the SCSI protocol transactionidentifier of the controller 101, the correspondence between the MACaddress of the back-end adapter 1014 and the SCSI protocol transactionidentifier of the controller 101 that is established by the establishingunit 1023′, to obtain the MAC address of the back-end adapter 1014. Theencapsulating and decapsulating unit 1022′ is further configured toencapsulate the SCSI protocol operation request response into anEthernet operation request response packet, where the Ethernet operationrequest response packet carries the MAC address of the back-end adapter1014. The first transceiver unit 1021′ is further configured to send theEthernet operation request response packet to the controller 101according to the MAC address of the back-end adapter 1014. In oneimplementation manner, a first field of the Ethernet operation requestpacket carries the SCSI protocol transaction identifier of thecontroller 101, and a second field of the Ethernet operation requestpacket carries the SAS protocol address of the target disk 1031, wherethe first field, the second field, and a field that is in the Ethernetoperation request packet and carries the SCSI protocol operation requestare three different fields. That the establishing unit 1023′ establishesa correspondence between the MAC address of the back-end adapter 1014and the SCSI protocol transaction identifier of the controller 101includes: the encapsulating and decapsulating unit 1022′ decapsulatesthe first field of the Ethernet operation request packet to obtain theSCSI protocol transaction identifier of the controller 101, and theestablishing unit 1023′ establishes the correspondence between the MACaddress of the back-end adapter 1014 and the SCSI protocol transactionidentifier of the controller 101. That the second transceiver unit 1024′sends the SCSI protocol operation request to the target disk 1031according to the SAS protocol address of the target disk 1031 includes:the encapsulating and decapsulating unit 1022′ decapsulates the secondfield of the Ethernet operation request packet, to obtain the SASprotocol address of the target disk 1031, and the second transceiverunit 1024′ sends the SCSI protocol operation request to the target disk1031 according to the SAS protocol address of the target disk 1031.

In another embodiment based on FIG. 3b , the first field of the Ethernetoperation request packet sent by the back-end adapter 1014 carries theSCSI protocol transaction identifier of the controller 101, and thesecond field carries the SAS protocol address of the target disk 1031,where in the Ethernet operation request packet, the first field, thesecond field, and a field carrying the SCSI protocol operation requestare three different fields; and the establishing unit 1023′ establishesthe correspondence between the MAC address of the back-end adapter 1014and the SCSI protocol transaction identifier of the controller 101,where the SCSI protocol transaction identifier of the controller 101 isobtained by the disk enclosure 102 from the first field by decapsulatingthe Ethernet operation request packet.

That the second transceiver unit 1024′ sends the SAS protocol address ofthe target disk in the SCSI protocol operation request to the targetdisk according to the SAS protocol address of the target disk includes:the encapsulating and decapsulating unit 1022′ decapsulates the Ethernetoperation request packet, to obtain the SAS protocol address of thetarget disk from the second field, and the second transceiver unit 1024′sends the SCSI protocol operation request to the target disk accordingto the SAS protocol address of the target disk obtained from the secondfield. In this way, without a need to parse the SCSI protocol operationrequest, the correspondence between the SCSI protocol transactionidentifier of the controller 101 and the MAC address of the back-endadapter 1014 can be established according to the SCSI protocoltransaction identifier of the controller 101 carried in the first field,and the SCSI protocol operation request can be directly sent to thetarget disk 1031 according to the SAS protocol address of the targetdisk 1031 carried in the second field.

An embodiment of the present invention provides a method that can beimplemented based on the structure shown in FIG. 2. As shown in FIG. 5Aand FIG. 5B, a detailed procedure of the method includes the followingsteps:

501: A central processing unit 1012 sends a SCSI protocol operationrequest to a back-end adapter 1014.

502: After receiving the SCSI protocol operation request, the back-endadapter 1014 queries a correspondence between a MAC address of a diskenclosure 102 and a SAS protocol address of a target disk 1031 to obtainthe MAC address of the disk enclosure 102, and encapsulates the SCSIprotocol operation request as an Ethernet operation request packet,where the Ethernet operation request packet carries a MAC address of theback-end adapter 1014 and the MAC address of the disk enclosure 102.

503: The back-end adapter 1014 sends the Ethernet operation requestpacket to the disk enclosure 102 according to the MAC address of thedisk enclosure 102.

504: The disk enclosure 102 receives and decapsulates the Ethernetoperation request packet, to obtain the SCSI protocol operation request,and establishes a correspondence between the MAC address of the back-endadapter 1014 and a SCSI protocol transaction identifier of thecontroller 101.

505: The disk enclosure 102 sends the SCSI protocol operation request tothe target disk 1031 according to the SAS protocol address of the targetdisk 1031.

After receiving the SCSI protocol operation request, the target disk1031 generates a SCSI protocol operation request response.

506: The disk enclosure 102 receives the SCSI protocol operation requestresponse that is sent by the target disk 1031 according to the SCSIprotocol operation request.

507: The disk enclosure 102 queries the correspondence between the MACaddress of the back-end adapter 1014 and the SCSI protocol transactionidentifier of the controller 101 according to the SCSI protocoltransaction identifier of the controller 101 to obtain the MAC addressof the back-end adapter 1014, and encapsulates the SCSI protocoloperation request response into an Ethernet operation request responsepacket that carries the MAC address of the back-end adapter 1014.

508: The disk enclosure 102 sends the Ethernet operation requestresponse packet to the controller 101 according to the MAC address ofthe back-end adapter 1014.

509: The back-end adapter 1014 receives and decapsulates the Ethernetoperation request response packet, to obtain the SCSI protocol operationrequest response.

510: The back-end adapter 1014 sends the SCSI protocol operation requestresponse to the central processing unit 1012.

In this embodiment, the back-end adapter 1014 of the controller 101 hasa MAC address, and the disk enclosure 102 also has a MAC address. Whenthe controller 101 communicates with the disk enclosure 102 using anEthernet network, a SCSI protocol command is encapsulated into anEthernet packet, and central processing units of the controller 101 andthe disk enclosure 102 do not use the TCP/IP protocol for encapsulationor decapsulation, thereby reducing layers of encapsulation ordecapsulation, reducing resource consumption of a central processingunit of a storage system, reducing a processing delay of the storagesystem, and improving performance of the storage system.

In a scenario of this embodiment of the present invention, to implementthat the controller 101 accesses any one of disks 1031 . . . 103 n, 1041. . . 104 n, a correspondence between the MAC address of the diskenclosure 102 and a SAS protocol address of each of the disks 1031 . . .103 n, 1041 . . . 104 n needs to be established on the controller 101,and the disk enclosure 102 needs to store the correspondence between theSCSI protocol transaction identifier of the controller 101 and the MACaddress of the back-end adapter 1014 in the controller 101. In thisembodiment of the present invention, after the storage system is poweredon, the back-end adapter 1024 of the controller 101 sends a heartbeatbroadcast packet that carries the MAC address of the back-end adapter1014 and the SCSI protocol transaction identifier of the controller 101.The heartbeat broadcast packet is used to collect the MAC address of thedisk enclosure 102 and the SAS protocol address of each of the disks1031 . . . 103 n, 1041 . . . 104 n that communicate with the diskenclosure 102 on one hand, and on the other hand update a state changeof the disks that communicates with the disk enclosure 102, such as anincrease or a decrease in the disks. The disk enclosure 102 collects theSAS protocol address of each of the disks 1031 . . . 103 n, 1041 . . .104 n. After receiving the heartbeat broadcast packet, the diskenclosure 102 sends a heartbeat broadcast packet response to theback-end adapter 1014, where the heartbeat broadcast packet responsecarries the MAC address of the disk enclosure 102 and the SAS protocoladdress of each of the disks 1031 . . . 103 n, 1041 . . . 104 n. Afterreceiving the heartbeat broadcast packet response sent by the diskenclosure 102, the back-end adapter 1014 of the controller 101establishes and stores the correspondence between the MAC address of thedisk enclosure 102 and the SAS protocol address of each of the disks1031 . . . 103 n, 1041 . . . 104 n.

As shown in FIG. 6, an implementation manner includes:

Step 601: A back-end adapter 1014 of a controller 101 sends a heartbeatbroadcast packet.

Step 602: A disk enclosure 102 receives the heartbeat broadcast packetsent by the back-end adapter 1014 of the controller 101.

Step 603: The disk enclosure 102 sends a heartbeat broadcast packetresponse to the controller 101.

Step 604: The back-end adapter 1014 of the controller 101 receives theheartbeat broadcast packet response sent by the disk enclosure 102.

Step 605: The back-end adapter 1014 obtains, by parsing the heartbeatbroadcast packet response, a MAC address of the disk enclosure 102 and aSAS protocol address of each of disks 1031 . . . 103 n, 1041 . . . 104n, and establishes a correspondence between the MAC address of the diskenclosure 102 and the SAS protocol address of each of the disks 1031 . .. 103 n, 1041 . . . 104 n.

Exemplarily, a packet format of the heartbeat broadcast packet sent bythe back-end adapter 1014 in step 601 is shown in FIG. 7. In theheartbeat broadcast packet sent by the back-end adapter 1014, a SCSIprotocol packet is also directly encapsulated into an Ethernet packetinstead of using the TCP/IP layer. As can be seen from FIG. 7, theheartbeat broadcast packet sent by the back-end adapter 1014 is used asan Ethernet packet and includes a destination MAC address field, asource MAC address field, and a payload. A source MAC address bitcarries the MAC address of the back-end adapter 1014. When the heartbeatbroadcast packet is used as a broadcast packet, each bit in thedestination MAC address field is 1. The payload of the heartbeatbroadcast packet carries another field. The payload may include multiplefields, for example, a SCSI protocol packet-type field that is used toindicate a type of a SCSI protocol operation request, such as a SCSIprotocol read operation request or a SCSI protocol write operationrequest; a SCSI protocol transaction identifier field that is used touniquely identify a specific SCSI protocol transaction link establishedbetween a controller and a disk; and a destination SAS protocol addressfield that is used to indicate receiving of a SAS protocol address of adisk that is encapsulated into the SCSI protocol operation request,where a SAS protocol address of a target disk receiving a current SCSIprotocol operation request can be recognized by using the field, withouta need to parse and query a SCSI protocol frame data field to determinethe SAS protocol address of the target disk. In the heartbeat broadcastpacket, each bit of the destination SAS address field is 0. The payloadfurther includes an operation code field, where the operation code fieldis used to indicate an operation type of a SCSI command and a datafield. In the heartbeat broadcast packet, the operation code field is0x050, which is used to indicate a broadcast packet. FIG. 7 shows apacket format of a heartbeat broadcast packet. After receiving theheartbeat broadcast packet, the disk enclosure 102 decapsulates anEthernet operation request packet, and determines, according toinformation carried in the destination SAS protocol address field, thatthe packet is a heartbeat broadcast packet, thereby improving a packetprocessing speed. In another implementation manner, a valid data fielddoes not include the SCSI protocol transaction identifier field, thedestination SAS protocol address field, or the SCSI protocol packet-typefield. The payload of the heartbeat broadcast packet includes the SCSIprotocol frame data field, where the SCSI protocol frame data fieldcarries the SCSI protocol operation request, and the SCSI protocoltransaction identifier of the controller 101 and the destination SASprotocol address that are carried in the heartbeat broadcast packet maybe obtained from the SCSI protocol frame data field of the heartbeatbroadcast packet. Although the heartbeat broadcast packet in an Ethernetoperation request packet format shown in FIG. 7 includes the destinationMAC address field, the source MAC address field, and the payload, for aperson skilled in the art, the Ethernet operation request packet mayfurther include another field as required, and the payload may furtherinclude another field as required, which are not described herein again.

Exemplarily, as shown in FIG. 8, in a packet format of the heartbeatbroadcast packet response sent by the disk enclosure 102 to thecontroller 101 in step 603, a destination MAC address field of theheartbeat broadcast packet response is the MAC address of the back-endadapter 1014, a source MAC address field carries the MAC address of thedisk enclosure 102, an operation code field is 0x060, and a payloadfurther includes a packet content identifier field that is used to carrya SAS protocol address of a disk that communicates with the diskenclosure 102.

Referring again to FIG. 6, in step 605, the back-end adapter 1014obtains, by parsing the heartbeat broadcast packet response, the MACaddress of the disk enclosure 102 and the SAS protocol address of eachof the disks 1031 . . . 103 n, 1041 . . . 104 n. As shown in FIG. 9, thecorrespondence between the MAC address of the disk enclosure 102 and theSAS protocol address of each of the disks 1031 . . . 103 n, 1041 . . .104 n is stored in the form of a two-dimensional table. In specificcomputer implementation, the two-dimensional table may be stored in theform of a two-dimensional array or in a form that can be recognized by acomputer, which is not limited by this embodiment of the presentinvention. The disk enclosure 102 sends the heartbeat broadcast packetresponse to the controller 101. The heartbeat broadcast packet responsemay carry the MAC address of the disk enclosure 102 and the SAS protocoladdresses of all the disks 1031 . . . 103 n, 1041 . . . 104 n, or theheartbeat broadcast packet response may carry the MAC address of thedisk enclosure 102 and SAS protocol addresses of some of the disks,where the correspondence between the MAC address of the disk enclosure102 and the SAS protocol address of each of the disks 1031 . . . 103 n,1041 . . . 104 n that is stored by the back-end adapter 1014 is updatedand improved by exchanging a heartbeat broadcast packet and a heartbeatbroadcast packet response between the controller 101 and disk enclosure102 for multiple times. When a new disk is connected in the diskenclosure 102, the disk enclosure 102 receives a heartbeat broadcastpacket sent by the controller 101, and sends, to the controller 101, aheartbeat broadcast packet response that carries the MAC address of thedisk enclosure 102 and a SAS protocol address of the new disk. In thisembodiment of the present invention, another expression of saving thecorrespondence between the SCSI protocol transaction identifier of thecontroller 101 and the MAC address of the back-end adapter 1014comprises storing the correspondence between the SCSI protocoltransaction identifier of the controller 101 and the MAC address of theback-end adapter 1014. Another expression of saving the correspondencebetween the MAC address of the disk enclosure 102 and the SAS protocoladdress of each of the disks 1031 . . . 103 n, 1041 . . . 104 ncomprises storing the correspondence between the MAC address of the diskenclosure 102 and the SAS protocol address of each of the disks 1031 . .. 103 n, 1041 . . . 104 n. Both expressions have a same meaning.

In this embodiment of the present invention, FIG. 10 shows a connectionrelationship between the central processing unit 1012 of the controller101 and the back-end adapter 1014 of the controller 101 in the schematicstructural diagram of the controller shown in FIG. 2. The front-endadapter 1011 and the back-end adapter 1014 communicate with the centralprocessing unit 1012 through Peripheral Component Interconnect Express(PCIe) switching. Certainly, the front-end adapter 1011 and the back-endadapter 1014 are connected through PCIe switching. The implementationfor communication with the central processing unit 1012 is only oneimplementation, and the communication may also be implemented by using asouth bridge chip, which is not limited herein.

The controller structure shown in FIG. 10 is used as an example. Thecentral processing unit 1012 of the controller 101 sends, to a targetdisk connected to the disk enclosure 102, a SCSI protocol operationrequest, such as a read operation request or a write operation request,which is not limited by the present invention. The SCSI protocoloperation request may be sent to the target disk by the centralprocessing unit 1012 according to an operation request that is receivedby the front-end adapter 1011 and sent by a server, which is not limitedherein. Exemplarily, a packet format of the SCSI protocol operationrequest is a standard SCSI protocol packet format, and the SCSI protocoloperation request carries a SCSI protocol transaction identifier of thecontroller 101 and a SAS protocol address of the target disk. Theback-end adapter 1014 receives the SCSI protocol operation request, andqueries a correspondence between a MAC address of the disk enclosure andthe SAS protocol address of the target disk according to the SASprotocol address carried in the SCSI protocol operation request. Forexample, the back-end adapter 1014 queries a two-dimensional tablerepresenting a correspondence between the MAC address of the diskenclosure 102 and a SAS protocol address of each of disks 1031 . . . 103n, 1041 . . . 104 n. In this embodiment of the present invention, thatthe SAS protocol address of the target disk carried in the SCSI protocoloperation request is a SAS protocol address of a disk 1031 is used as anexample. A correspondence between the disk enclosure 102 and the SASprotocol address of the target disk 1031 is queried according to the SASprotocol address of the target disk 1031, to obtain the MAC address ofthe disk enclosure 102.

Exemplarily, as shown in FIG. 11, a structure of the back-end adapter1014 includes a PCIe interface, a Direct Memory Access (DMA) engine, aninput/output state maintenance module, a protocol encapsulating anddecapsulating module, and an Ethernet module. The PCIe interface is usedto implement data transmission with a PCIe interface of the centralprocessing unit 1012, for example, receiving a SCSI protocol operationrequest sent by the central processing unit 1012. The DMA engine is anoptional structure in the back-end adapter 1014, and may directly readdata from a memory 1013 of the controller or directly write data intothe memory 1013 of the controller according to a SCSI protocol packettype and a memory address carried in the SCSI protocol operationrequest. The input/output state maintenance module is used to collectand maintain a correspondence between the MAC address of the diskenclosure and a SAS protocol address of a disk, for example, storing atwo-dimensional table used to represent a correspondence between the MACaddress of the disk enclosure 102 and a SAS protocol address of each ofdisks 1031 . . . 103 n, 1041 . . . 104 n. The input/output statemaintenance module is used to query, according to a SAS protocol addressof a target disk carried in the SCSI protocol operation request receivedthrough the PCIe interface, a MAC address of a disk enclosure in whichthe target disk is located, where the disk enclosure in which the targetdisk is located refers to a disk enclosure in which the target disk isplaced. For meaning of placing, refer to the foregoing description. Inthis embodiment of the present invention, the SAS protocol address ofthe target disk carried in the SCSI protocol operation request is a SASprotocol address of a disk 1031, and a queried MAC address of a diskenclosure corresponding to the SAS protocol address of the target disk1031 is the MAC address of the disk enclosure 102. The SCSI protocoloperation request and the MAC address of the disk enclosure 102 are sentto the protocol encapsulating and decapsulating module. As shown in FIG.11, the protocol encapsulating and decapsulating module encapsulates theSCSI protocol operation request into a SCSI protocol frame data field,the SAS protocol address of the target disk 1031 is encapsulated into adestination SAS protocol address field, a SCSI protocol operationrequest type is encapsulated into a SCSI protocol packet-type field, aSCSI protocol transaction identifier of the controller 101 isencapsulated into a SCSI protocol transaction identifier field, and theSCSI protocol packet-type field, the SCSI protocol transactionidentifier field, the destination SAS protocol address field, and theSCSI protocol frame data field are encapsulated into a payload of anEthernet operation request packet, where in the Ethernet operationrequest packet, a destination MAC address field carries the MAC addressof the disk enclosure 102, and a source MAC address field carries a MACaddress of the back-end adapter 1014. In the payload of the Ethernetoperation request packet, the destination SAS protocol address field,the SCSI protocol transaction identifier field, and the SCSI protocolframe data field carrying the SCSI protocol operation request are threedifferent fields. In another implementation manner, the payload of theEthernet operation request packet does not include the SCSI protocoltransaction identifier field or the destination SAS protocol addressfield, and the disk enclosure 102 obtains the SAS address of the targetdisk 1031 and the SCSI protocol transaction identifier of the controller101 from the SCSI protocol operation request carried in the SCSIprotocol frame data field. The Ethernet module sends the Ethernetoperation request packet to the disk enclosure 102 by using an Ethernetnetwork. The Ethernet module includes a flow control module, a packetretransmission module, an Ethernet MAC module, and an Ethernetinterface. The flow control module is configured to perform flow controlprocessing when data congestion occurs on the Ethernet network, to avoiddata packet loss caused by Ethernet congestion; the packetretransmission module is configured to retransmit a packet when a packettransmission error occurs on the Ethernet network, to ensure reliabilityof data transmission; and the Ethernet MAC module and the Ethernetinterface, serving as an Ethernet MAC layer and an Ethernet physicalinterface layer, have a same meaning as an Ethernet MAC layer and anEthernet physical interface layer in a standard Ethernet networkstructure.

The input/output state maintenance module is further configured tocreate and maintain an input and output state according to the SCSIprotocol packet-type field of the SCSI protocol operation request duringa process of executing the SCSI protocol operation request. Exemplarily,an input and output state table may be used to record a transactionexecution state of the SCSI protocol operation request, to avoid a SCSIprotocol operation request conflict. In this embodiment of the presentinvention, when the Ethernet operation request packet is sent to thedisk enclosure 102, the transaction execution state of the SCSI protocoloperation request is recorded as establishing a link with a SCSIprotocol transaction of the target disk 1031 and executing the SCSIprotocol transaction.

The front-end interface 1021 of the disk enclosure 102 shown in FIG. 3areceives an Ethernet operation request packet that is sent by theback-end adapter 1014 and carries the MAC address of the disk enclosure102 and the MAC address of the back-end adapter 1014, and decapsulatesthe Ethernet operation request packet. A type of a SCSI protocoloperation request can be obtained according to a SCSI protocolpacket-type field in a payload. For example, a type of the SCSI protocolpacket type is a SCSI protocol read operation request. A SCSI protocoltransaction identifier can be obtained according to the SCSI protocoltransaction identifier field in the payload, to establish acorrespondence between the SCSI protocol transaction identifier and theMAC address of the back-end adapter 1014, and the SAS protocol addressof the target disk 1031 can be obtained according to the destination SASprotocol address field in the payload. The disk enclosure 102 may sendthe SCSI protocol operation request to the target disk 1031 according tothe SAS protocol address of the target disk 1031, without a need toparse the SCSI protocol frame data field. Therefore, computationresources used by the disk enclosure 102 to perform protocol processingare reduced, a protocol processing speed is improved, and performance ofa storage system is improved. In another implementation manner, if thepayload of the Ethernet operation request packet does not have the SCSIprotocol transaction identifier field and the destination SAS protocoladdress field, after decapsulating the Ethernet operation requestpacket, the disk enclosure obtains the SCSI protocol operation requestfrom the payload, parses the SCSI protocol operation request to obtainthe SCSI protocol transaction identifier and the SAS protocol address ofthe target disk, establishes the correspondence between the SCSIprotocol transaction identifier and the MAC address of the back-endadapter 1014, and sends the SCSI protocol operation request to thetarget disk 1031 according to the SAS protocol address of the targetdisk 1031 through the back-end interface 1024.

After the Ethernet operation request packet carrying the SCSI protocoloperation request is decapsulated, the MAC address of the back-endadapter 1014 is obtained. The SCSI protocol transaction identifier isobtained according to the SCSI protocol transaction identifier field inthe payload. The central processing unit 1022 establishes thecorrespondence between the MAC address of the back-end adapter 1014 andthe SCSI protocol transaction identifier of the controller 101. Theback-end interface 1024 sends the SCSI protocol operation request to thetarget disk 1031 according to the SAS protocol address of the targetdisk 1031 carried in the destination SAS protocol address field in thepayload. The central processing unit 1022 receives, through the back-endinterface 1024, a SCSI protocol operation request response sent by thetarget disk 1031, where the SCSI protocol operation request responsecarries the SCSI protocol transaction identifier of the controller 101,and queries the correspondence between the MAC address of the back-endadapter 1014 and the SCSI protocol transaction identifier of thecontroller 101 according to the SCSI protocol transaction identifier ofthe controller 101 carried in the SCSI protocol operation requestresponse. The front-end interface 1021 receives the SCSI protocoloperation request response sent by the central processing unit 1022, andthe front-end interface 1021 encapsulates the SCSI protocol operationrequest response into an Ethernet operation request response packet,where the Ethernet operation request response packet carries the MACaddress of the back-end adapter 1014 and the MAC address of thefront-end interface 1021. For example, a destination MAC address fieldcarries the MAC address of the back-end adapter 1014, a source MACaddress field carries the MAC address of the disk enclosure 102, a SCSIprotocol transaction identifier field carries the SCSI protocoltransaction identifier of the controller 101, and a SCSI protocolpacket-type field carries a type of the SCSI protocol operation request.In this embodiment of the present invention, the Ethernet operationrequest response packet may also be called an Ethernet response packetfor the Ethernet operation request packet, and both have a same meaning.In one implementation manner, in a payload of the Ethernet operationrequest response packet, a SCSI protocol frame data field carries theSCSI protocol operation request response; the SCSI protocol transactionidentifier field of the payload carries the SCSI protocol transactionidentifier of the controller; and the SCSI protocol packet-type field ofthe payload carries the type of the SCSI protocol operation request.

The back-end adapter 1014 of the controller 101 receives the Ethernetoperation request response packet sent by the disk enclosure 102, anddecapsulates the Ethernet operation request response packet, to obtainthe SCSI protocol operation request response. The input/output statemaintenance module of the back-end adapter 1014 determines whether theSCSI protocol operation request response is valid according to the SCSIprotocol transaction identifier carried in the SCSI protocol operationrequest and a transaction execution state of the SCSI protocol operationrequest, which are recorded in the input/output state maintenancemodule. When it is determined that the Ethernet operation requestresponse packet carries the SCSI protocol transaction identifier of thecontroller 101, the SCSI protocol operation request response isconsidered valid. The input/output state maintenance module of theback-end adapter 1014 updates the transaction execution state of theSCSI protocol operation request to be that the execution of the SCSIprotocol transaction is complete and the link with the SCSI protocoltransaction of the target disk 1031 is released. If a SCSI protocoltransaction can be completed only when the SCSI protocol transactionincludes multiple SCSI protocol operation request responses, theinput/output state maintenance module of the back-end adapter 1014further needs to count the number of received SCSI protocol operationrequest responses. When the Ethernet operation request response packetdoes not carry the SCSI protocol transaction identifier of thecontroller 101, the SCSI protocol operation request response isdiscarded. That the Ethernet operation request response packet does notcarry the SCSI protocol transaction identifier of the controller 101includes: the Ethernet operation request response packet does not carrythe SCSI protocol transaction identifier of the controller 101, or theSCSI protocol transaction identifier of the controller 101 carried inthe Ethernet operation request response packet is inconsistent with theSCSI protocol transaction identifier of the controller 101. In oneimplementation manner, the SCSI protocol transaction identifier can beobtained from the SCSI protocol transaction identifier field in thepayload of the Ethernet operation request response packet. In anotherimplementation manner, if the payload of the Ethernet operation requestresponse packet does not include the SCSI protocol transactionidentifier field, the SCSI protocol transaction identifier of thecontroller 101 is obtained from the SCSI protocol frame data field ofthe payload. The back-end adapter 1014 sends the SCSI protocol operationrequest response to the central processing unit 1012.

During an actual implementation process, the back-end adapter 1014 shownin FIG. 10 of the embodiment, as a logical structure, may be an ASICcommercial chip or an FPGA, and includes a central processing unit and amemory, or a part of the back-end adapter 1014 may include both an ASICcommercial chip and an FPGA, and includes a first interface, a secondinterface, a memory, and a first central processing unit. The firstinterface is configured to receive a SCSI protocol operation requestsent by the central processing unit 1012. The SCSI protocol operationrequest carries a SAS protocol address of a target disk 1031. The firstcentral processing unit executes a computer instruction in the memory,querying a correspondence between a MAC address of a disk enclosure 102and the SAS protocol address of the target disk 1031 according to theSAS protocol address of the target disk 1031 to obtain the MAC addressof the disk enclosure 102, and encapsulating the SCSI protocol operationrequest into an Ethernet operation request packet. The Ethernetoperation request packet carries a MAC address of the back-end adapter1014 and the MAC address of the disk enclosure 102.

Further, the Ethernet operation request packet further includes a firstfield and a second field. The first field is used to carry a SCSIprotocol transaction identifier. The second field is used to carry theSAS protocol address of the target disk. In the Ethernet operationrequest packet, the first field, the second field, and a field carryingthe SCSI protocol operation request are three different fields. As shownin FIG. 12, the first field is a SCSI protocol transaction identifierfield in a payload of the Ethernet operation request packet, the secondfield is a destination SAS protocol address field in the payload, andthe field carrying the SCSI protocol operation request in the payload isa SCSI protocol frame data field. For descriptions of other fields inFIG. 12, refer to descriptions of an Ethernet operation request packet,an Ethernet operation request response packet, a heartbeat broadcastpacket, and a heartbeat broadcast response packet in the embodiments.

The second interface is configured to send the Ethernet operationrequest packet to the disk enclosure 102 according to the MAC address ofthe disk enclosure 102. The second interface is further configured toreceive an Ethernet response packet for the Ethernet operation requestpacket that is sent by the disk enclosure 102, where the Ethernetresponse packet for the Ethernet operation request packet carries theMAC address of the back-end adapter 1014. The first central processingunit executes the computer instruction in the memory, decapsulating theEthernet response packet for the Ethernet operation request packet toobtain a SCSI protocol operation request response and the firstinterface is further configured to send the SCSI protocol operationrequest response to the central processing unit 1012. Further, theEthernet response packet for the Ethernet operation request packetfurther carries the SCSI protocol transaction identifier of thecontroller 101. The first central processing unit executes the computerinstruction in the memory, recording a transaction execution state ofthe SCSI protocol operation request. When the Ethernet operation requestpacket is sent to the disk enclosure 102, recording the transactionexecution state of the SCSI protocol operation request as establishing alink with a SCSI protocol transaction of the target disk 1031 andexecuting the SCSI protocol transaction.

Further, the first central processing unit executes the computerinstruction in the memory, updating, according to the SCSI protocoloperation request response, the transaction execution state of the SCSIprotocol operation request to be that the execution of the SCSI protocoltransaction is complete and the link with the SCSI protocol transactionof the target disk 1031 is released.

Further, the first central processing unit executes the computerinstruction in the memory, discarding the SCSI protocol operationrequest response when the Ethernet operation request response packetdoes not carry the SCSI protocol transaction identifier of thecontroller 101.

Further, the first interface is a PCIe interface.

A back-end adapter 1014 shown in FIG. 11 may be logically dividedaccording to a structure shown in FIG. 13, and includes a firsttransceiver unit 1301, a querying unit 1302, an encapsulating anddecapsulating unit 1303, and a second transceiver unit 1304. The firsttransceiver unit 1301 is configured to receive a SCSI protocol operationrequest sent by a central processing unit 1012, where the SCSI protocoloperation request carries a SAS protocol address of a target disk 1031.The querying unit 1302 is configured to query a correspondence between aMAC address of a disk enclosure 102 and the SAS protocol address of thetarget disk 1031 to obtain the MAC address of the disk enclosure 102.The encapsulating and decapsulating unit 1303 is configured toencapsulate the SCSI protocol operation request into an Ethernetoperation request packet, where the Ethernet operation request packetcarries a MAC address of the back-end adapter 1014 and the MAC addressof the disk enclosure 102. The second transceiver unit 1304 isconfigured to send the Ethernet operation request packet to the diskenclosure 102 according to the MAC address of the disk enclosure 102.Further, the SCSI protocol operation request further carries a SCSIprotocol transaction identifier of the controller 101, and theencapsulating and decapsulating unit 1303 is further configured toencapsulate the SCSI protocol transaction identifier of the controller101 into a first field of the Ethernet operation request packet, andencapsulate the SAS protocol address of the target disk into a secondfield, where the first field, the second field, and a field that is inthe Ethernet operation request packet and carries the SCSI protocoloperation request are three different fields.

Further, the second transceiver unit 1304 is further configured toreceive an Ethernet response packet for the Ethernet operation requestpacket that is sent by the disk enclosure 102, where the Ethernetresponse packet for the Ethernet operation request packet carries theMAC address of the back-end adapter 1014. Further, the encapsulating anddecapsulating unit 1303 is further configured to decapsulate theEthernet response packet for the Ethernet operation request packet, toobtain a SCSI protocol operation request response. The first transceiverunit 1301 is further configured to send the SCSI protocol operationrequest response to the central processing unit 1012. The back-endadapter 1014 further includes a recording unit 1304 that is configuredto record a transaction execution state of the SCSI protocol operationrequest. When the Ethernet operation request packet is sent to the diskenclosure 102, the recording unit 1304 records the transaction executionstate of the SCSI protocol operation request as establishing a link witha SCSI protocol transaction of the target disk 1031 and executing theSCSI protocol transaction. Further, the recording unit 1304 is furtherconfigured to update, according to the SCSI protocol operation requestresponse, the transaction execution state of the SCSI protocol operationrequest to be that the execution of the SCSI protocol transaction iscomplete and the link with the SCSI protocol transaction of the targetdisk 1031 is released. Further, the first transceiver unit 1301 isfurther configured to discard the SCSI protocol operation requestresponse when the Ethernet operation request response packet does notcarry the SCSI protocol transaction identifier of the controller 101.

Further, the correspondence between the MAC address of the diskenclosure 102 and the SAS protocol address of the target disk 1031 isestablished by the back-end adapter 1014 according to resourceinformation sent by the disk enclosure 102, where the resourceinformation includes the MAC address of the disk enclosure 102 and theSAS protocol address of the target disk 1031, and is implemented using aheartbeat broadcast packet response sent by the disk enclosure 102.

Further, the controller 101 and the disk enclosure 102 described in thisembodiment of the present invention may form a storage system shown inFIG. 14, where the storage system includes multiple controllers 101 andmultiple disk enclosures 102. The number of the controllers 101 and thenumber of the disk enclosures 102 may be determined according to anactual requirement. The multiple controllers 101 communicate with themultiple disk enclosures 102 using an Ethernet switch 100. In addition,a redundancy relationship is formed between the controllers 101 toimprove reliability. Flexible system expansion can be implemented usingthe controllers 101 and disk enclosures 102 provided by this embodimentof the present invention.

In this embodiment of the present invention, both the SCSI protocoloperation request and the SCSI protocol operation request response areSCSI protocol packets. The SAS protocol is an interface protocol, thatis, a serial SCSI protocol is used, and devices using SAS interfaces usethe SCSI protocol for communication. In this embodiment of the presentinvention, disks 1031 . . . 103 n, 1041 . . . 104 n are disks using SASprotocol interfaces, a disk enclosure 102 also uses a SAS protocolinterface to connect to the disks 1031 . . . 103 n, 1041 . . . 104 n,and the disk enclosure 102 communicates with the disks 1031 . . . 103 n,1041 . . . 104 n using the SCSI protocol. A SCSI protocol transactionlink is a link established for communication between an initiator and atarget in the SCSI protocol, and the link is released when thecommunication ends, thereby releasing SCSI protocol resources. Ato-be-executed transaction for which the link is established is a SCSIprotocol transaction, that is, a corresponding SCSI protocol operationrequest.

In this embodiment of the present invention, a SCSI protocol transactionidentifier is encapsulated into a first field of the Ethernet operationrequest packet, which is described as that the first field of theEthernet operation request packet carries the SCSI protocol transactionidentifier of the controller; and the SAS protocol address of the targetdisk is encapsulated into a second field of the Ethernet operationrequest packet, which is described as that the second field of theEthernet operation request packet carries the SAS protocol address ofthe target disk.

Descriptions of the central processing unit and the first centralprocessing unit used in this embodiment of the present invention areonly used to clearly indicate that the central processing unit and thefirst central processing unit belong to different apparatuses, and thecentral processing unit and the first central processing unit may be asame processor or different processors, which is specifically selectedaccording to technical requirements and is not limited by thisembodiment of the present invention.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions.

It may be clearly understood by a person skilled in the art that, forthe purpose of convenient and brief description, for a detailed workingprocess of the foregoing system, apparatus, and unit, refer to acorresponding process in the foregoing method embodiments, and detailsare not described herein again.

In the several embodiments provided in the present application, itshould be understood that the disclosed system and method may beimplemented in other manners. For example, the described apparatusembodiment is merely exemplary. For example, the unit division is merelylogical function division and may be other division in actualimplementation. For example, a plurality of units or components may becombined or integrated into another system, or some features may beignored or not performed. In addition, the displayed or discussed mutualcouplings or direct couplings or communication connections may beimplemented through some interfaces. The indirect couplings orcommunication connections between the apparatuses or units may beimplemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentinvention may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

When the functions are implemented in the form of a software functionalunit and sold or used as an independent product, the functions may bestored in a computer-readable non-volatile storage medium. Based on suchan understanding, the technical solutions of the present inventionessentially, or the part contributing to the prior art, or some of thetechnical solutions may be implemented in a form of a software product.The software product is stored in a non-volatile storage medium, andincludes several instructions for instructing a computer device (whichmay be a personal computer, a server, or a network device) to performall or some of the steps of the methods described in the embodiments ofthe present invention. The foregoing non-volatile storage mediumincludes: any medium that can store a program code, such as a USB flashdrive, a removable hard disk, a read-only memory (ROM), a magnetic disk,or an optical disc.

The foregoing descriptions are merely specific implementation manners ofthe present invention, but are not intended to limit the protectionscope of the present invention.

What is claimed is:
 1. A computer-readable medium comprisingcomputer-readable instructions for causing a disk enclosure to: receiveand decapsulate an Ethernet operation request packet sent by acontroller to obtain a Small Computer System Interface (SCSI) protocoloperation request, wherein multiple disks are connected in the diskenclosure and each disk in the disk enclosure is connected to the diskenclosure using a Serial Attached Small Computer System Interface (SAS)protocol, wherein the controller comprises a central processing unit anda back-end adapter, wherein the controller communicates with the diskenclosure using an Ethernet network, wherein the disk enclosure and theback-end adapter each have a media access control (MAC) address, whereinthe Ethernet operation request packet carries the MAC address of theback-end adapter and the MAC address of the disk enclosure, and whereinthe SCSI protocol operation request carries a SCSI protocol transactionidentifier of the controller and a SAS protocol address of a targetdisk; and send the SCSI protocol operation request to the target diskaccording to the SAS protocol address of the target disk.
 2. Thecomputer-readable medium according to claim 1, further comprisingcomputer-readable instructions for causing the disk enclosure to:establish a correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controller;receive a SCSI protocol operation request response that is sent by thetarget disk according to the SCSI protocol operation request, whereinthe SCSI protocol operation request response carries the SCSI protocoltransaction identifier of the controller; query the correspondencebetween the MAC address of the back-end adapter and the SCSI protocoltransaction identifier of the controller according to the SCSI protocoltransaction identifier of the controller, to obtain the MAC address ofthe back-end adapter; encapsulate the SCSI protocol operation requestresponse into an Ethernet operation request response packet, wherein theEthernet operation request response packet carries the MAC address ofthe back-end adapter; and send the Ethernet operation request responsepacket to the controller according to the MAC address of the back-endadapter.
 3. The computer-readable medium according to claim 2, wherein afirst field of the Ethernet operation request packet carries the SCSIprotocol transaction identifier of the controller and a second field ofthe Ethernet operation request packet carries the SAS protocol addressof the target disk, wherein the first field, the second field, and afield that is in the Ethernet operation request packet and carries theSCSI protocol operation request are three different fields, and furthercomprising computer-readable instructions for causing the disk enclosureto: decapsulate the first field of the Ethernet operation request packetto obtain the SCSI protocol transaction identifier of the controller;establish the correspondence between the MAC address of the back-endadapter and the SCSI protocol transaction identifier of the controller;decapsulate the second field of the Ethernet operation request packet toobtain the SAS protocol address of the target disk; and send the SCSIprotocol operation request to the target disk according to the SASprotocol address of the target disk.
 4. A computer-readable mediumcomprising computer-readable instructions for causing a back-end adapterof a controller of a storage system to: receive a Small Computer SystemInterface (SCSI) protocol operation request, wherein the SCSI protocoloperation request carries a Serial Attached Small Computer SystemInterface (SAS) protocol address of a target disk, wherein multipledisks are connected in a disk enclosure and each disk in the diskenclosure is connected to the disk enclosure using the SAS protocol, andwherein the back-end adapter communicates with the disk enclosure of thestorage system using an Ethernet network; send a Ethernet operationrequest packet to a disk enclosure of the storage system according to aMAC address of the disk enclosure, wherein the disk enclosure and theback-end adapter each have a media access control (MAC) address andwherein the back-end adapter stores a correspondence between the MACaddress of the disk enclosure and a SAS protocol address of each disk inthe disk enclosure; query a correspondence between the MAC address ofthe disk enclosure and the SAS protocol address of the target diskaccording to the SAS protocol address of the target disk; obtain the MACaddress of the disk enclosure; and encapsulate the SCSI protocoloperation request into an Ethernet operation request packet, wherein theEthernet operation request packet carries the MAC address of theback-end adapter and the MAC address of the disk enclosure.
 5. Thecomputer-readable medium according to claim 4, wherein the SCSI protocoloperation request further carries a SCSI protocol transaction identifierof the controller, the SCSI protocol transaction identifier of thecontroller is encapsulated into a first field of the Ethernet operationrequest packet and the SAS protocol address of the target disk isencapsulated into a second field, and wherein the first field, thesecond field, and a field that is in the Ethernet operation requestpacket and carries the SCSI protocol operation request are threedifferent fields.
 6. The computer-readable medium according to claim 5further comprising computer-readable instructions for causing theback-end adapter to: receive an Ethernet response packet for theEthernet operation request packet that is sent by the disk enclosure,wherein the Ethernet response packet for the Ethernet operation requestpacket carries the MAC address of the back-end adapter, the back-endadapter further comprising: decapsulate the Ethernet response packet forthe Ethernet operation request packet to obtain a SCSI protocoloperation request response; and send the SCSI protocol operation requestresponse to the central processing unit.
 7. The computer-readable mediumaccording to claim 6 further comprising computer-readable instructionsfor causing the back-end adapter to: record a transaction executionstate of the SCSI protocol operation request when the Ethernet operationrequest packet is sent to the disk enclosure, with recording thetransaction execution state of the SCSI protocol operation request asestablishing a link with a SCSI protocol transaction of the target diskand executing the SCSI protocol transaction.
 8. The computer-readablemedium according to claim 7 further comprising computer-readableinstructions for causing the back-end adapter to: update, according tothe SCSI protocol operation request response, the transaction executionstate of the SCSI protocol operation request to be that the execution ofthe SCSI protocol transaction is complete and the link with the SCSIprotocol transaction of the target disk is released.
 9. Thecomputer-readable medium according to claim 7 further comprisingcomputer-readable instructions for causing the back-end adapter to:discard the SCSI protocol operation request response when the Ethernetresponse packet for the Ethernet operation request packet does not carrythe SCSI protocol transaction identifier of the controller.